ALFIX Stairway Tower 4.0
The wide range of ALFIX stairway towers allows for quick and safe access, offering comprehensive solutions for any scaffold need, whether as a construction site stairway (200 kg m2), a second emergency escape route or a public access stairway tower (500 kg/m2 or 750 kg/m2). The stairway towers are based on the ALFIX MODUL MULTI 4.0 and ALFIX MODUL METRIC 4.0 modular scaffolding systems. As part of design optimisations, the connector heads of the 4.0 tube ledgers and the U-ledgers have been reinforced to enhance the load transfer capacity. By using high-strength materials and enhancing product details, the load bearing capacity of the stairway tower has increased considerably. At the same time, there has been a cut down in the total cost as fewer materials are needed. Furthermore, the wide range of MODUL standards with the respective tube connectors also allow the use of the stairway tower as a suspended scaffold for excavation works, shafts in mining, etc.
Renovation works at the Teutoburger school in Osnabrück required the installation of two temporary emergency stairway towers to serve as a second escape route. In order to enable the client to do the precise preliminary planning using technical documents that were provided by the project team of ALFIX GmbH, the geometry of the stairway towers was designed together with building contractor and client WALKE + ACKER GmbH based upon the site conditions. One of the stairway towers needed to have an opening of at least 3.0 m wide at ground level as an escape route. With the flexible ALFIX MODUL MULTI 4.0 system, the dimensional requirements could be fully met, both longitudinally and transversely. Due to our comprehensive range of stair stringers, comprising the bracket for the starter step and the stair stringers 0.50 m right up to 1.50 m, any exit height the project demanded could be constructed exactly as required.
With the stair stringers with a height of 0.50 m, height differences of 0.50 m between the flights can easily be levelled at the platforms. Additionally, stair stringers with a height of 1.0 m and 1.50 m allow for flexibility when having to adapt the structure to different height grids. As ALFIX MODUL MULTI 4.0 has bay lengths of up to 3.0 m, any required passageways and escape route widths in the stairway tower could be built using standard components. With a width of 1.57 m, the scaffold walkway has a larger width than the prescribed minimum stair width for emergency stairs, making the stairs more comfortable and safer to use.
In order to meet the high load capacity demands, double standards and combinations of multiple standards were installed in some parts of the stairway towers to maintain the storey heights of 2.50 m between the platforms in the stairway tower and to transfer the loads safely to the ground. The uppermost exit platform of each stairway tower was installed at a height of 11.35 m. Each tower had a further two exit platforms on intermediate levels. The second required stairway tower was also designed with a scaffold walkway width of 1.57 m.
The load-bearing capacity of 750 kg/m² can easily be achieved using ALFIX steel decks in standard dimension. All requirements were met using standard components of the ALFIX MODUL MULTI 4.0 scaffolding system allowing for the project to be realised in an economical and a resource-efficient way. If a construction project requires walkways to be wider than 2.07 m with a live load of 750 kg/m², then specially reinforced stair stringers will have to be installed, which can be custom manufactured in accordance with the requirements of each building project. Maximum flexibility can be attained with the provision of customised stair stringers and guardrails, enabling perfect adaptability to both the ground conditions and the building structure.
ALFIX provided detailed and customised assembly plans along with the respective parts lists from the ALFIX stairway tower, and made sure the order was picked, ready for loading and delivered to the construction site within a short period of time. Comprehensive proof of structural stability of both individual parts and the entire scaffolding structure was provided to the customer by ALFIX engineers. The implementation of the assembly plans supplied ensures that high live loads of towers open to the public can be transferred accordingly. For more information and a checklist for a stairway tower project inquiry, please refer to our catalogue “ALFIX Stairway Towers” in the download section of our website www.alfix-systems.com.
Special requirements apply to the use of second emergency escape routes made of modular scaffolding systems in kindergartens, nursery schools and similar settings: in accordance with the specifications of the local fire protection authorities and state building regulations, continuous children’s handrails must be installed at a height of about 60 cm to 70 cm.
Additionally, risers must be installed to close the gap between the steps. The stairway tower must be designed to provide safe access and have constant stair risers, regardless of any uneven ground conditions. This can be achieved easily due to the adjustable base jacks and the bracket for the starter step. ALFIX provides handrails for children, starter steps and risers for both modular scaffolding systems allowing for comprehensive project planning of a safe and economical stairway tower as an emergency escape route for public areas.
